GUEST EDITOR IN SPECIAL ISSUES
NANOMATERIALS (MDPI)
Nanobubbles
Guest Editors: G.Z. Kyzas, A.C. Mitropoulos
2021
The main purpose of this Special Issue is to collect top theoretical and experimental works on nanobubbles and provide a collection of the newest research achievements in this important field. It is widely known that the most common definition for nanobubbles (NBs) is that they are nanoscopic gaseous cavities with a diameter of less than 1 μm. Nanobubbles (NBs) is a generic term to describe two distinguished cases of bubbles in a liquid—surface and bulk bubbles being in the nanoscale size. Surface nanobubbles (SNBs) refer to a pocket-like space filled with gas with a height no less than 10 nm and the area that it occupies ranging from 7850 to 78,500 nm2. In the case of bubbles with a size less than 1 μm suspended in a liquid, the term bulk nanobubble (BNBs) is used instead. The nanoscale dimension and composition challenge the development of new imaging, tracing, and analytical techniques operating in situ with high spatial and time resolutions. Additionally, today, there are numerous applications in various commercial fields employing heterogeneous catalysis, electrochemistry, photochemistry, coating processes, lake management, wastewater treatment, cleaning, immersion lithography, general separation processes, as well as biomedicine and drug delivery, steadily attracting increasing interdisciplinary attention. This Special Issue on “Nanobubbles” seeks high-quality works and topics focusing on (but not limited to) the latest approaches to nanobubbles. All researchers working in the field of nanobubbles are cordially invited to contribute original papers (research or review articles, etc.) to this Special Issue of Nanomaterials.
NANOMATERIALS (MDPI)
Nanomaterials and nanotechnology in wastewater treatment
Guest Editors: G.Z. Kyzas, A.C. Mitropoulos
2020
The rapidly increasing population, depleting water resources, and climate change resulting in prolonged droughts and floods have rendered drinking water as a competitive resource in many parts of the world. Therefore, any form of water, reuse or recycle will help to mitigate this challenge. Municipal, industrial, and natural activities produce large quantities of liquid wastes and effluents which pose severe threats to the environment and human health. Some indicative/conventional methods are: biological treatments, adsorption, flocculation, oxidation, membranes, filtration, etc. These conventional technologies focus only on the primary wastewater treatment, especially on the physical separation of solid particles and release high concentration of toxic phosphorus, nitrogen, and other ionic compounds into the environment. Thus, latest technology involving Nanotechnology is highly potent in advancing wastewater treatment via Nanomaterials (nanoadsorbents, nanocomposites (photo)catalysts, nanofiltration, nanomembranes, nanoparticles, etc). These nanomaterials have been established in the development of separation membranes, catalytic, and adsorbent materials to enhance the removal of specific components of wastewater and improve productivity. All above can be achieved by using Nanotechnology. This Special Issue seeks high-quality works and topics (not only those) focusing on the latest approaches based on Nanotechnology to efficiently treat wastewaters.
POLYMERS (MDPI)
Polymeric materials for water and wastewater management
Guest Editors: G.Z. Kyzas, A.C. Mitropoulos
2019
Water is crucial point of interests nowadays due to its special management. On the other hand, wastewaters is one of the important pollution type of the water environment. The careful management of water and wastewater is a big challenge and “hot” trend of recent research. During the last century, a huge amount of wastewater was discharged into rivers, lakes, and coastal areas. This resulted in serious pollution problems in the aqueous environments. So, it mandatory to find the appropriate technique in order to efficiently treat and manage water and wastewaters. Some indicative/typical methods are biological treatments, adsorption, flocculation, oxidation, membranes, and filtration. All of the above can be achieved by using polymeric materials (polymeric adsorbent materials, polymeric flocculants, polymeric filters, polymeric membranes, polymeric composites, etc).
This Special Issue on “Polymeric Materials for Water and Wastewater Management” seeks high-quality works and topics focusing on (but not restricted to) the latest approaches to the management of water and wastewaters including biological, chemical, adsorption, flocculation, oxidation, membranes, and filtration using polymeric materials.
APPLIED SCIENCES (MDPI)
Treatment of industrial effluents
Guest Editors: G.Z. Kyzas
2019
Industrial effluents are one of the important pollution sources in the pollution of the water environment. During the last century, a huge amount of those effluents was discharged into rivers, lakes, and coastal areas. This resulted in serious pollution problems. There are many types of industrial effluents based on different industries and contaminants; each sector produces its own particular combination of pollutants. Like the various characteristics of industrial effluents, their treatment must be designed specifically for the particular type of effluent produced. The amount of effluents depends on the technical level of process in each industry sector and will be gradually reduced with the improvement of industrial technologies. The increasing rates of industrial effluents in developing countries are thought to be much higher than those in developed countries. This fact predicts that industrial wastewater pollution, as a mean environment pollution problem, will move from developed countries to developing countries in the early 21st century. So, it is mandatory to find the appropriate technique in order to efficiently treat those effluents. Some indicative/typical methods are biological treatments, adsorption, flocculation, oxidation, membranes, filtration, etc. This Special Issue seeks high-quality works and topics (not only those) focusing on the latest approaches to the treatment of industrial effluents, including biological, chemical, adsorption, flocculation, oxidation, membranes, filtration, etc.
PROCESSES (MDPI)
Green separations and extraction processes
Guest Editors: G.Z. Kyzas, K.A. Matis
2019
There has been much talk, from various perspectives (including even political), about going green. The explosion in the number of recent relevant publications may be explained by this heightened interest. For instance: ionic liquids were used in the extraction of phenolic compounds from bio-oils. Ionic liquids, also termed “green” and “designer” solvents, were proposed as promising solvents for diverse applications, including metal extraction. The economic aspect of the recovery of useful valuable minerals or metals, contributing to recycling meanwhile with environmental technology constitutes the focus of various applications. A number of technologies for the conversion of lignocelluloses into gas, liquid, and solid fuels, as well as platform chemicals, are being researched (i.e., for the production of green diesel and gasoline).
Green environmentally friendly adsorbents from agro-food wastes were also synthesized and tested – i.e., for the treatment of pharmaceutical effluents. Green synthesis of amino-functionalized carbon nanotube-graphene hybrid aerogels was prepared for high-performance heavy metal ion removal. Membranes based on functionalized ionic liquids also attracted attention for CO2 (which mainly comes from flue gas, natural gas, and syngas) separation. Various guidance tools and practices have been proposed to improve the sustainability of mining activity, while maintaining the economic viability. The above brief introduction justifies the importance of this Special Issue.
PROCESSES (MDPI)
Wastewater treatment processes
Guest Editors: G.Z. Kyzas, K.A. Matis
2019
Cheap and plentiful, water was for centuries a manufacturing tool that industry took for granted. However, population growth, globalization, and climate change are shepherding in a new water-constrained era. The food-chain pyramid may receive contaminants of either surface water or ground water around industrial and residential communities (e.g., metals, pesticides, pharmaceuticals, etc.) through man’s activities and on top of the pyramid, man (perhaps) receives pre-concentrated toxicity. A common example constitutes Bangladesh, where millions of people consumed drinking water with arsenic concentrations—exceeding the guideline values of WHO. Good, clean water just cannot be replaced—and it is becoming harder to come by. Typical processes that are investigated and applied to wastewater treatment can be the following: Biological, adsorption, flocculation, oxidation, membranes, filtration, and so on, including the nanotechnological. This Special Issue on “Wastewater Treatment Processes” seeks high-quality works and topics (not only those) focusing on the latest novel wastewater processes, including biological, adsorption, flocculation, oxidation, membranes, filtration, etc.
JOURNAL OF CHEMISTRY (HINDAWI)
Environmental chemistry: Remediation of radioactively
contaminated sites
Guest Editors: R.O. Abdel Rahman, M.I. Ojovan, G.Z. Kyzas, Y.-T. Hung
2019
The spread of contamination problems worldwide and their eıects on the natural resources led to the evolution of the environmental chemistry sciences. This evolution relies on the integrations of inorganic, organic, physical, and analytical chemistry to facilitate the scientiÿc investigations of the contamination extent and optimize remediation eıorts.The heterogeneous nature of the contamination sources, contaminant migration, and contaminated areas add to the complexity of remediation process. Optimization of remediation efforts represents a real challenge for workers in this ÿeld, where improvements are still needed in current characterization and monitoring techniques and remediation technologies.
This special issue is directed to cover different aspects of environmental chemistry related to the assessment and application of green sustainable remediation technologies for radioactively contaminated sites. Submissions related to radioactive contamination characterization and green remediation of those sites are especially welcome. Current state-of-the-art original research articles of characterization and monitoring of radioactive contaminated sites are encouraged.
MATERIALS (MDPI)
Green activated carbons
Guest Editors: G.Z. Kyzas
2018
Activated carbons are considered to be the most successful adsorbent materials due to their high adsorption capacity for the majority of pollutants (dyes, heavy metals, pharmaceuticals, phenols, etc.). They possess large surface areas, and different surface functional groups, which include carboxyl, carbonyl, phenol, quinone, lactone, and other groups, bound to the edges of the graphite-like layers. Therefore, they are regarded as good adsorbents, both in liquid and gas phases. The most widely-used carbonaceous materials for the industrial production of activated carbons are coal, wood, and coconut shell. These types of precursors are quite expensive and often imported, in many places; hence making it necessary, particularly for developing countries, to find a cheap and available feedstock for the preparation of activated carbon for use in industry, drinking water purification and wastewater treatment. In order to reduce the synthesis cost of activated carbons, some green final products are recently proposed, using several suitable agricultural by-products (lignocellulosics) as activated carbon precursors. In this Special Issue, special attention is given to those activated carbons (synthesis, and adsorption applications) which can be characterized as “green” because their origin and green environmental-friendly sources. Furthermore, the application of activated carbons cannot be only adsorption in liquid- or gas-phase (metals, dyes, CO2, NOx, etc.), and also other proposed applications.
PROCESSES (MDPI)
Advances in bioseparation engineering
Guest Editors: G.Z. Kyzas, K.A. Matis
2014
Bioprocesses are known to treat raw materials and thereby generate useful products. The individual operations, or even steps within a process which change or separate components, are called unit operations. For instance, in a typical fermentation process, raw materials are altered significantly by reactions occurring in the reactor. Nevertheless, before and after fermentation, physical changes are carried out that are important in order to prepare materials/substrates for the reaction, and also to extract and purify the desired product(s) from the culture broth.
The concept of unit operations embodies many different methods of separating mixtures and hence, represents a major advance in chemical technology. Over time, however, those and subsequent concepts have evolved into a unified field of separation processes; certainly, there are several major gains in gaining insight into the capability and efficiency from viewing separation processes as a unified field. In this regard, sustainability in this field and its significance for the chemical and process industry has been recently examined. We would be very pleased to receive your valuable contributions in this field.
ADVANCES IN MATERIALS SCIENCE AND ENGINEERING (HINDAWI)
Novel approaches in designing natural/synthetic materials for environmental applications
Guest Editors: G.Z. Kyzas, S. Azizian, M. Kostoglou
2014
Bioprocesses are known to treat raw materials and thereby generate useful products. The individual operations, or even steps within a process which change or separate components, are called unit operations. For instance, in a typical fermentation process, raw materials are altered significantly by reactions occurring in the reactor. Nevertheless, before and after fermentation, physical changes are carried out that are important in order to prepare materials/substrates for the reaction, and also to extract and purify the desired product(s) from the culture broth.
The concept of unit operations embodies many different methods of separating mixtures and hence, represents a major advance in chemical technology. Over time, however, those and subsequent concepts have evolved into a unified field of separation processes; certainly, there are several major gains in gaining insight into the capability and efficiency from viewing separation processes as a unified field. In this regard, sustainability in this field and its significance for the chemical and process industry has been recently examined. We would be very pleased to receive your valuable contributions in this field.